Go script to generate base matrix for regex based images

main.go

package main

import (
	"fmt"
	"math"
	"sync"
)

type Matrix struct {
	matrix [][]int
}

var increment_map = [][]int{{0, 0}, {1, 0}, {1, 1}, {0, 1}}

var wc sync.WaitGroup

func main() {
	m := NewMatrix(5)
	fmt.Println(m)
}

func NewMatrix(size int) *Matrix {
	m := &Matrix{}
	size = int(math.Pow(2.0, float64(size)))
	m.matrix = make([][]int, size)
	for i, _ := range m.matrix {
		m.matrix[i] = make([]int, size)
	}
	wc.Add(1)
	go m.Generate(size, 0, 0, 0)
	wc.Wait()
	return m
}

func (m *Matrix) Generate(size int, x int, y int, code int) {
	if size > 1 {
		newSize := size >> 1
		wc.Add(4)
		for i, inc := range increment_map {
			go m.Generate(newSize, x+inc[0]*newSize, y+inc[1]*newSize, code*10+i+1)
		}
	} else {
		m.matrix[y][x] = code
	}
	defer wc.Done()
}

func (m *Matrix) String() string {
	var out string
	for i, _ := range m.matrix {
		for j, _ := range m.matrix[i] {
			out = fmt.Sprintf("%s%d ", out, m.matrix[i][j])
		}
		out = out + "\n"
	}
	return out
}